No idea about Mac program but The + - can be put on the tool bar any where you like (almost) from the 3 Bar Menu far right top your will see it there then if you go to Customize that is where you can put it any where is best. Have a read of this it is very detailed in pics, they took the video off though. https://www.howtogeek.com/333110/how-to-customize-firefox-quantum-and-remove-the-white-space-around-the-title-bar/ And just to make sure The Address Bar has 3 Dots. click on them for Tools Please let us know if this solved your issue or if need further assistance.